The ischemic-proliferative retinopathies, most notably diabetic retinopathy, are a leading cause of blindness in America today. As a consequence, a great deal of effort is being focused on the pathogenesis of the vaso-proliferative response in an attempt to inhibit this response and its deleterious affects. A major factor hindering these efforts has been the lack of success in creating an experimental model for a chronic ischemic-proliferative retinopathy. We have conducted a pilot study using radiation of the posterior segment of capuchin monkey eyes to produce an ischemic retinopathy. Follow up studies using fluorescein angiography and electron microscopy showed that a vasoproliferative response occurred which in some respects resembles diabetic retinopathy. We believe that the use of radiation seems promising for the establishment of a primate model of a chronic ischemic-proliferative retinopathy. The objectives of the present application are two-fold. First, we wish to determine whether the model of chronic ischemic-proliferative retinopathy produced in our pilot studies is reproducible. Secondly, we wish to study this model with careful clinicopathologic correlations, comparing fundus photography and fluorescein angiography with light and electron microscopy. This analysis may allow us to better understand the process leading to retinal neovascularization, tissue destruction and blindness. Furthermore, the primate model could also be used to evaluate and to develop new therapeutic protocols for the ischemic-vasoproliferative retinopathies.